Recommended Larger Wheel/Radial Tire for Boat Trailer with 4.80 x 8 Tires

Question:

Need tire for small boat trailer has 4.80x8 bias tires im looking to possibly go up a size or two and maybe a radial for longer distance and higher speed travels any advice looking for rim and tire. Thanks

asked by: Allen C

Expert Reply:

A 4.80/4.00-8 tire like # AM10002 would have a diameter somewhere in the neighborhood of 16 inches. They're typically mounted on a 8 x 3-3/4 inch wheel with a 4 lug on 4 inch bolt pattern.

Going 'up' by 2 sizes for a radial tire would give you a ST145/R12 tire on a 12 x 4 inch wheel with a tire diameter of 21.3 inches which will put your tire about 2-1/2 inches closer to your fender. To avoid the tire bottoming out on the underside of the fender, we like to see a minimum of 3-4 inches of clearance between the tire and fender on a loaded trailer. You might need to either raise or replace the fender with something like # CE19500-2 for plastic fenders (sold in pairs) or # CE17701G for a steel fender.

If you were wanting to go with a 12 inch wheel, the radial # AM35351DX is what I'd recommend. This is a ST145/R12 tire mounted on a 12 x 4 inch wheel with a 4 on 4 bolt pattern. The radial tire has a 1220 lb per tire/2440 lb per axle weight capacity. The tire carries a 65 mph speed rating, which is typical for this size of wheel/tire. Radial tires are more prevalent on larger sized tires, so this is what I'd recommend for you.

expert reply by: Mike L